Revoking a Zero Downtime Upgrade

1. A method comprising: initiating revocation of a zero downtime upgrade procedure upgrading a source system to a target system, wherein the zero downtime upgrade procedure prepares software for the target system in parallel to operations of the source system by selectively (i) renaming source tables of the source system, (ii) cloning the renamed source tables of the source system for the target system, (iii) equipping the cloned renamed source tables of the source system with database triggers to transfer data to target tables used by the source system according to a source database schema, (iv) generating the target tables comprising updated software content for later use by the target system while the source tables of the source system are used via a bridge database schema, and (v) sharing tables between the source database schema accessed via the bridge database schema and the target system; stopping upgrade activities at the target system; stopping production activities at the source system; dropping at least a portion of the target tables and revoking any associated table structure changes; switching at least a portion of the target tables from use by the target system to use by the source system; and connecting the source system to the source database schema to enable use of the source system in its state prior to an initiation of the zero downtime upgrade procedure.

2. The method of claim 1 , wherein the stopping of the upgrade activities at the target system comprises at least one of: stopping upgrade dialog instances, removing limitations on writing for at least a portion of the shared tables, or dropping the cloned renamed source tables of the source system and dropping database triggers on the source tables of the source system.

3. The method of claim 1 , wherein the stopping of the production activities at the source system comprises at least one of: finishing batch jobs, logging off users, or running any queues until the queues become empty.

4. The method of claim 1 , wherein the dropping of the at least a portion of the target tables and revoking any associated table structure changes comprises at least one of: dropping the cloned renamed source tables of the source system, dropping pre-defined fields added to at least one of the generated target tables, or deleting at least a portion of content added to tables shared by the source system and the target system.

5. The method of claim 1 , wherein the switching of the at least a portion of the target tables from use by the target system to use by the source system comprises renaming at least one table according to a format used by the source database schema.

6. The method of claim 1 , wherein the connecting of the source system to the source database schema comprises starting production instances and enabling users to login.

7. The method of claim 1 , further comprising: removing any artifacts associated with the zero downtime upgrade procedure.

8. The method of claim 7 , wherein the artifacts comprise at least one of: an alias of a table, a view of a table, the bridge database schema, or objects temporarily created by the zero downtime upgrade procedure for the duration of the zero downtime upgrade procedure.

9. A method comprising: initiating revocation of a zero downtime upgrade procedure upgrading a source system to a target system, wherein the zero downtime upgrade procedure prepares software for the target system in parallel to operations of the source system by selectively (i) renaming source tables of the source system, (ii) cloning the renamed source tables of the source system for the target system, (iii) equipping the cloned renamed source tables of the source system with database triggers to transfer data to target tables used by the source system according to a source database schema, (iv) generating the target tables comprising updated software content for later use by the target system while the source tables of the source system are used via a bridge database schema, and (v) sharing tables between the source database schema accessed via the bridge database schema and the target system; stopping upgrade activities at the target system; stopping production activities at the source system; dropping the target tables and revoking any associated table structure changes; switching at least a portion of the target tables from use by the target system to use by the source system; and connecting the source system to the source database schema to enable use of the source system in its state prior to an initiation of the zero downtime upgrade procedure.

10. The method of claim 9 , wherein the stopping of the upgrade activities at the target system comprises at least one of: stopping upgrade dialog instances, removing limitations on writing for at least a portion of the shared tables, or dropping the cloned renamed source tables of the source system and dropping database triggers on the source tables of the source system, and wherein the stopping of the production activities at the source system comprises at least one of: finishing batch jobs, logging off users, or running any queues until the queues become empty.

11. The method of claim 9 , wherein the dropping of the target tables and revoking any associated table structure changes comprises at least one of: dropping the cloned renamed source tables of the source system, dropping pre-defined fields added to at least one of the generated target tables, or deleting at least a portion of content added to tables shared by the source system and the target system.

12. The method of claim 9 , wherein the switching of the at least a portion of the target tables from use by the target system to use by the source system comprises at least one of: renaming at least one table or creating an alias for at least one of the target tables.

13. The method of claim 9 , wherein the connecting of the source system to the source database schema comprises suspending all actions by users, disconnecting from a bridge database schema bridging the source database schema to a target database schema, and connecting to the source database schema.

14. The method of claim 9 , further comprising: removing any artifacts associated with the zero downtime upgrade procedure.

15. The method of claim 14 , wherein the artifacts comprise at least one of: an alias of a table, a view of a table, the bridge database schema, or objects temporarily created by the zero downtime upgrade procedure for the duration of the zero downtime upgrade procedure.

16. A system comprising: at least one data processor; and a memory storing instructions which, when executed by the at least one data processor, result in operations comprising: initiating revocation of a zero downtime upgrade procedure upgrading a source system to a target system, wherein the zero downtime upgrade procedure prepares software for the target system in parallel to operations of the source system by selectively (i) renaming source tables of the source system, (ii) cloning the renamed source tables of the source system for the target system, (iii) equipping the cloned renamed source tables of the source system with database triggers to transfer data to target tables used by the source system according to a source database schema, (iv) generating the target tables comprising updated software content for later use by the target system while the source tables of the source system are used via a bridge database schema, and (v) sharing tables between the source database schema accessed via the bridge database schema and the target system; stopping upgrade activities at the target system; stopping production activities at the source system; dropping the target tables and revoking any associated table structure changes; switching at least a portion of the target tables from use by the target system to use by the source system; and connecting the source system to the source database schema to enable use of the source system in its state prior to an initiation of the zero downtime upgrade procedure.

17. The system of claim 16 , wherein the stopping of the upgrade activities at the target system comprises at least one of: stopping upgrade dialog instances, removing limitations on writing for at least a portion of the shared tables, or dropping the cloned renamed source tables of the source system and dropping database triggers on the source tables of the source system, and wherein the stopping of the production activities at the source system comprises at least one of: finishing batch jobs, logging off users, or running any queues until the queues become empty.

18. The system of claim 16 , wherein the dropping of the target tables and revoking any associated table structure changes comprises at least one of: dropping the cloned renamed source tables of the source system, dropping pre-defined fields added to at least one of the generated target tables, or deleting at least a portion of content added to tables shared by the source system and the target system.

19. The system of claim 16 , wherein the switching of the at least a portion of the target tables from use by the target system to use by the source system comprises at least one of: renaming at least one table or creating an alias for at least one of the target tables.